#include<stdio.h>
#include<string.h>
int main(){
	int alphabetic(char);
	int longest(char[ ]);
	int i;
	char line[100];
	printf("input one line:\n");
	gets(line);
		printf(" ");
	for(i=longest(line);alphabetic(line[i]);i++)
	printf("%c",line[i]);
	printf("  \n");
	return 0;
}
int alphabetic(char c)
{
	if((c>='a'&&c<='z')||(c>='A'&&c<='z'))
	return(1);
	else

	return(0);
}
int longest(char string[  ])
{
	int len=0,i,length=0,flag=1,place=0,point;
	for(i==0;i<=strlen(string);i++)
	
	if(alphabetic(string[i]))
	if (flag)
	{point=i;
	flag=0;
	}
	else
	len++;
	else{
		flag=1;
		if(len>=length)
		{
			length=len;
			place=point;
			len=0;
		}
	
	}
	return(place);
	
}
